JSON to TypeScript

JSON to TypeScript Interface Generator

When you're wiring up an API in a typed codebase, hand-writing interfaces for every response is tedious and error-prone. This JSON to TypeScript generator reads any JSON payload and produces matching interface definitions automatically — inferring strings, numbers, booleans, arrays, and nested objects so your editor gets full autocomplete and type checking.

How it works

The tool runs entirely in your browser. Paste a JSON sample and it walks the structure locally, inferring a type for each field and generating clean, nested interfaces you can copy straight into a .ts file. Arrays are analyzed to infer their element type, and nested objects become their own named interfaces. Because it's pure client-side JavaScript, nothing is uploaded and results appear instantly.

How to use it

• Grab a representative JSON response from your API.
• Paste it into the input box.
• Copy the generated interfaces into your project.
• Rename the root interface to match your domain model.

For best results, feed in JSON that's already clean — tidy it first with the JSON Formatter or check it with the JSON Validator. Working across formats? Convert the same data with JSON to YAML for config files too.

Private by design

Your payloads often contain real data, so privacy matters. This tool never sends your JSON anywhere — no upload, no account, no tracking. It's free and runs on any modern browser, including on your phone, so you can generate types from sample data without exposing it.